The molds for food products known in the prior art conventionally comprise aluminum foil which gives certain rigidity to the mold whether the conditions are dry or damp. However, this type of mold is not biodegradable.
Additionally, because of the presence of aluminum, such molds cannot be used in microwave ovens and they are not suitable for use in production lines which include metal detectors.
In order to solve these problems, paper-based molds were developed. Although the resistance of such paper-based molds to the required cooking temperature of food products is satisfactory, such molds have the disadvantage of losing their initial shape in the presence of moisture. In fact, conservation period of a food product in air-tight container, in some cases with modified atmosphere and at fridge temperatures moisture coming from the food products diffuses into the paper of the mold and thus causes the rims thereof to sag.
It is known as such to improve such paper-based molds by incorporating an outer layer of plastic on the paper-based layer, such as polyethylene terephthalate (PET). A shortcoming of using PET is that PET is not biodegradable and cannot be composted.
In publication GB 2443810A there is shown a packaging material comprises a compostable substrate, such as paperboard, provided with a surface film, also of compostable material, on an external surface of the substrate. The surface film may be cellophane, polylactic acid, polyhydroxybutyric acid or polyhydroxylvaleric acid amongst numerous others mentioned. Lamination may be by means of a compostable adhesive. This kind of a structure where the substrate is provided with a film of compostable material has a shortcoming that typically such a film is substantially incompressible and poorly stretchable, which makes it difficult process in converting process.
It is an object of the invention to provide a multilayer article, a behavior of which as a food accessory and/or mold of a food product is considerably improved. It is also an object of the invention to provide a method of manufacturing a multilayer article, by means of which a food accessory and/or a mold of a food product may be produced with good usability.